We fixed our today's infrastructure problems and our services should be fully operational. You should be able to log in using google authentication.

There is also possible to log in via other auth mechnism (twitter, fb, github and Vertabelo Academy itself) and access to the same Academy account. To do this you should choose the same email address as you used with google auth, but it is important that you have to confirm that this is the same account by log in by original method first.